“…By construction, these operators are exact on P r and, in general, they can be extended to the functional space F. In virtue of classical theorems in approximation theory, this procedure greatly improves the convergence order of the initial operator Q n in the space F. After its introduction in [9,10] for Bernstein operators (see also [7]), it has been extended by several authors to various classical linear approximation operators. For example by P. Mache and M.W.…”